Method for power adaptation in an electricity network

ABSTRACT

According to the invention, power matching in an electricity grid (N) is carried out by regulation of a storage power station (S) which is operated in the grid. In the event of changes in the power available or in the power consumption in the grid, the power consumption of the power consuming machine (V) in the storage power station is adapted so as to maintain equilibrium between the total power generation and the total power consumption. Power matching by regulation of the power load can be carried out around one order of magnitude more quickly than power matching by regulation of power generating machines (G 1,  G 2,  G 3,  GS) which act on the grid, and saves alternating thermal loads in the power stations.

TECHNICAL FIELD

The present invention relates to a method for power matching in anelectricity grid, as claimed in the precharacterizing clause of claim 1.

PRIOR ART

The power consumption of the energy loads and the power output of theelectricity generators must be kept in equilibrium within narrow limitsin an electricity grid in order to avoid overfrequencies orunderfrequencies in the grid, which can each lead to total failure. Inthis case, it must be possible to react to very fast changes at thegenerating end and at the demand end. In liberalized electricitymarkets, coverage for transient power demands, such as those which occurwhen a major load is connected or disconnected, but which really occurwhen a major power station block fails, is very highly lucrative. A verylarge amount of money can be earned even by purely providing appropriatecapacities. The capability to support the frequency is questionable whenelectricity generating systems fail. In the first fractions of a secondfollowing the failure of an electricity supply, the grid frequency canbe kept within the permissible tolerance in a large grid without anyproblem just by the rotating masses of the remaining power stations.However, after this, power reserves must be available immediately inorder to prevent underfrequency, and thus failing of the entire grid.Steam power stations which can be operated on a slightly throttled-backbasis can provide power in the order of magnitude of around 5% of theirmaximum power very quickly; however, they require several tens ofminutes to cope with power increases beyond this up to, for example, 30%of their maximum power. When a major load is connected to grid, thepower stations have to cope with load ramps in which it is necessary toprovide considerable additional power in the region of seconds or inless than ten minutes. Gas turbine systems and combination systems allowsuch increases to be coped with within minutes. An air turbine or acombined air/gas turbine in a storage power station of the cited typehas a comparable reaction. It is also known from experience in operationthat rapid load changes such as these result in high temperaturegradients and, as a consequence of this, in damaging alternating thermalloads and mechanical stresses particularly in the hot gas path, which isalready highly thermally loaded in any case, in gas turbine sets, or inthe steam generators of steam and combination power stations. All thenon-steady-state power demands must also be satisfied in an electricitygrid, for stable and reliable operation. Particularly in liberalizedelectricity markets, it is very highly advantageous not only for a gridoperator but also for a power station operator to have resources in hisportfolio to satisfy all of these load demands. Geodetic hydroelectricpower stations are admittedly able to mobilize significant powerreserves within seconds; however, their availability is, of course,limited. According to the prior art, different power station types aretherefore required to satisfy the different requirements, drivinginvestment costs to a high level.

DESCRIPTION OF THE INVENTION

One object of the present invention is thus to specify a method of thetype mentioned initially, which avoids the disadvantages of the priorart. The invention is based in particular on the object of specifyingone possible way to carry out power matching in an electricity grid whenrapid changes occur both at the power generating end and at the demandend, in as efficient a manner as possible. In this case, the aim is toprovide a capability to react both to sudden changes and to steep loadramps.

According to the invention, this object is achieved by use of thetotality of the features from claim 1.

Against the background of an electricity grid which, in addition to twoor more power loads and power generators, has a storage system which hasat least one power-consuming machine and a power-generating machine, theinvention is thus to react to transients in the power generated or thepower consumption in the grid by appropriate adaptation of the powerconsumed in the power consuming machine, and to reproduce an equilibriumbetween the power generated and the power consumption in the grid bythis control action or at least with its support. In practice, it hasbeen found that load gradients of around at least one order of magnitudemore can be achieved by regulation of or even switching off the powerconsuming machine, by means of a control action on the power generatingmachine in the storage system. In one preferred method variant, thepower output of the power generating machine and of the other powerstations in the grid is, in a first step, kept constant; in a largerelectricity grid, when a power station is disconnected from the grid ora load is connected to the grid, the available frequency supportcapacities which are kept available to a limited extent, particularly insteam power stations, are in fact activated in parallel. Furthermore,power matching by means of the power consuming machine in a storagesystem has the advantage that the power transient per se has no effectin a thermally highly loaded power generating structure, but on aconsiderably less loaded power consuming structure. Air storage systemscan be used in particular for this purpose since these intrinsicallyhave, for example, separately arranged turbines and compressors, as wellas a store in which compressed fluid is temporarily stored in order todrive the power generating machine and is available even when the powerconsuming machine is at rest or is consuming a reduced power. The poweroutput of all the power generating machines which act on the grid ispreferably kept constant in a first step, unless they have specialfrequency supporting capabilities.

A first advantageous initial operating state of the machines which areconnected to the grid is that in which the power consuming machine andthe power generating machine in a storage system are operated in a firstequilibrium state between power generation and power consumption of thegrid such that the mass flow which is conveyed to the storage volume isequal to the mass flow which flows out of the storage volume via thepower generating machine in the storage system; this allows constantcontinuous operation. In this case, the power consuming machine isadvantageously operated on a partial load, for example at 50% of itsmaximum power consumption. At the same time, the storage volume ispreferably filled to between 25% and 75%, with this percentage beingrelated to the difference between a minimum and a maximum permissiblepressure in the storage volume for operation of the storage system. Thismode of operation still makes it possible to change the powerconsumption of the power consuming machine in either direction when alack of equilibrium occurs, that is to say in the direction of anincreased or reduced power consumption.

Another initial operating state of the machines which are connected tothe grid, in which the maximum capability is provided for suddenlyincreasing the power in order to support the frequency or for a powerramp, is an operating state in which the power consuming machine in astorage system is being operated at maximum power. The entire powerconsumption of the power consuming machine can thus in principle be madeavailable to the grid simply by opening a switch. In a second step, thepower of the power generating machine in the storage system can beincreased, albeit considerably more slowly, if it is not being operatedat maximum power in the initial operating state. With regard to thestorage system, an initial operating state to this extent appears to bedesirable in which the power consuming machines are run at full powerconsumption, and the power generating machines are stationary or areidling. In absolute terms, an initial operating state such as thisactually provides the greatest potential to increase the power. However,the proportion of the power to be applied by the power generatingmachines is available only with a delay since power generating machineswhich are idling—or to be more precise their generators—must first ofall be synchronized to the grid. In the interest of maximum powerdynamic response, it has therefore been found to be advantageous to keepthe power generating machines in a state in which they are alreadysynchronized to the grid, but with a low power output to the grid. Thus,in a very particularly preferred operating method, all of the powerconsuming machines in at least one storage system which is connected tothe grid are operated at at least 80% of their maximum powerconsumption. At the same time, all the power generating machines in thisstorage system are synchronized to the grid, and are operated at a poweroutput which is as low as possible, preferably of less than 10% or evenless than 20% of their maximum power output; however, operating reasonsmay also demand a higher minimum power. Starting from this initialoperating state, it is possible to switch the power consuming machinesoff by opening switches when a rapid power demand occurs, and at thesame time to issue a power increasing command to the power generatingmachines. The power previously being consumed by the power consumingmachines is then instantaneously available to the grid, and the power ofthe power generating machines is made available with a delay time thatis intrinsic to the system and in particular with a power gradient whosemaximum gradient is limited, but without having to wait forsynchronization in advance. The power dynamic response for a situationin which there is rapid reduction in the power output or an increase inthe power consumption in the grid is thus maximized.

If two or more storage systems are available in the grid, it would alsobe possible to operate one of the systems with the power consumingmachine consuming the maximum power and one with the minimum powerconsumption, such that each of the systems can react in onedirection—excess power or lack of power—by regulation of the powerconsuming machine.

One fundamental idea of the invention is to use the power consumingmachine that is feeding a store to apply a secondary power consumption,which can in principle be switched off as required, in addition to theactual power loads in an electricity grid, in the form of a bias, andfor the net available power to be increased when required virtuallyinstantaneously by reducing or by switching off the secondary powerconsumption. The power output of the power generating machine in thestorage and in the other power stations in the grid can in this case bekept constant, at least in a first step. Conversely, as explained above,it is also possible to increase this secondary power consumption veryquickly in order to react to excess power intrinsically existing in thegrid without having to take rapid control actions in the power stationsconnected to the grid.

In the case of the method according to the invention, it is also highlyadvantageous for the power stations which are connected to the grid todelay the original power transients in a subsequent step of the method,and to carry them out more slowly, and for the power consuming machinesto be returned back to an initial operating state in order to reproducethe capability to react to a lack of power equilibrium in the grid.

The extremely wide load regulation range which a storage system, inparticular an air storage system, can cope with for power matchingaccording to the invention in an electricity grid is worth mentioning.Specifically, based on a rule of thumb that around two thirds of thegross turbine power in a gas turbine is consumed in the compressor, itcan easily be estimated that, based on steady-state operation of thesystem when in equilibrium, 200% of the instantaneous net power outputis available instantaneously by switching off the compressors! Theentire load regulation range of the system can then—based on thecompressor being designed for steady-state operation at equilibrium withthe power generating machine as 100%—be suddenly changed to a net poweroutput of −200% to +300% of the rated power that is available whenoperating at equilibrium A range of 200% of the system rated load can becovered just by compressor regulation, which can be carried out veryquickly and without any additional load on high-temperature components.This range could be extended even further by an appropriately largerdesign of the compressor, in which case partial load operation, forexample of a turbocompressor, can be coped with very efficiently byspeed regulation—in fact, the compressor need not be operated insynchronism with the grid.

In a corresponding manner, in one embodiment of the method, when a powergenerating system is disconnected from the grid or an additional load isconnected to the grid, the power consumption of the power consumingmachine is reduced in a first step, or is completely disconnected fromthe grid. In this case, the frequency supporting capability of otherpower stations can be activated at the same time. In a further step, thepower output of other power stations or of the power generating machinein the storage system can be increased considerably more slowly, withthe power consumption of the power consuming machine also beingincreased to the same extent, and at the same time. Conversely, when aload is disconnected from the grid, the power consumption of the powerconsuming machine is increased in a first step, in order to maintain theequilibrium between power generation and power consumption in the grid.Then, in a further step, and likewise considerably more slowly than thepower consuming machine reacts in a first step, the power generationfrom other power stations is reduced and the power consumption of thepower consuming machine is reduced to the same extent.

Further advantageous effects and embodiments of the invention willbecome evident in the light of the exemplary embodiment described in thefollowing text, or are specified in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail in the following textwith reference to exemplary embodiments which are illustrated in thedrawing, and in which, in detail:

FIG. 1 shows an electricity grid which can be operated according to theinvention;

FIG. 2 shows an example of the embodiment of a storage power station;

FIG. 3 shows an example of an operating concept for a storage powerstation such as this as a function of the net power output; and

FIG. 4 shows an example of power output dynamic response which can beachieved according to the invention.

In this case, the described exemplary embodiments represent only a minorinstructive detail of the invention as characterized in the claims.

APPROACH TO IMPLEMENTATION OF THE INVENTION

FIG. 1 shows an electricity grid N, highly schematically. Loads M1 toM8, three power stations or their generators G1 to G3, and an airstorage power station S are connected to the electricity grid via gridswitches 8. An air storage power station such as this has beendisclosed, for example, from DE 28 22 575, which disclosure representsan integral component of the present invention. The air storage powerstation S has at least one compressor V for filling a storage volume 100with an energy storage fluid, as well as a turbine T which can beoperated with the fluid from the storage volume 100. The turbine Tdrives a generator GS which produces electrical power which can be fedinto the electricity grid via the switch 112. The compressor V is drivenby a motor MS, which consumes a controllable amount of electrical powervia the switch 111 and the regulator 114. The difference between thepower output of the generator GS and the power consumption of the motorMS is fed into the grid N via the switch 113, as the net power output ofthe storage power station S. If the power consumption of the compressorV or of its drive motor MS is greater than the power produced in thegenerator GS, the storage power station S draws power from the grid viathe switch 113. In a first operating state, all the power loads M1 to M8and all the generators G1 to G3 as well as the storage power station Sare connected to the grid. The power consumption of all the loads M1 toM8 and of the drive motor MS, and the power output of all the powerstations G1 to G3 and of the generator GS are matched at nominal gridfrequency. Equilibrium between the power consumption and the poweroutput exists in the grid. If one of the power stations G1 to G3 fails,if a load is connected or if a load is disconnected from the grid, thisresults in a lack of equilibrium, which leads to overfrequency orunderfrequency in the grid, unless an immediate control action is takenfor power matching. According to the invention, the particularcapabilities of the storage power station S are used for this action,since it can act both as a power load and as an electricity generator.It has been found to be very particularly advantageous for the powermatching to be carried out by means of a control action on the powerconsuming machine V in the storage power station. If, for example, forwhatever reasons one of the power stations G1 to G3 is disconnected fromthe grid by opening the grid switch, the power budget within the grid isno longer balanced, and the grid frequency reacts to this by failing.Normally, the power stations which are still connected to the grid reactto this and increase the power as quickly as possible in order tosupport the frequency. As described initially, the capabilities of powerstations to react quickly differ widely. Furthermore, such rapid loadchanges on power stations result in structural loads on expensive powerstation components. In addition, the corresponding power reserves mustbe maintained, which leads to expensive investments not being fullyutilized, and power stations not running at their best operating pointduring normal operation. Overall, these factors make it very expensiveto maintain and produce power for frequency support and to satisfy steepload ramps. From the technical point of view, it would, of course, infact be desirable to first of all disconnect appropriate power loadsfrom the grid when a power station fails, although, for obvious reasons,this is not possible without problems. The invention equally makes useof the capability to disconnect loads from the grid, for example in theevent of a failure of power generating capacities, but without affectingone of the numerous loads M1 to M8 in the process. This is achieved bythe specific method of operation of the storage power station S asdescribed in the following text. As described in the introduction, anair storage power station S as illustrated is operated in the storagemode at times when the loads are low, for example at night or over theweekend. The switch 112 is opened and the switch 111 is closed, suchthat the motor MS drives the power consuming machine, the compressor V,which passes air or some other energy storage fluid into the storagevolume 100. No fluid flows out of the storage volume 100. The storagepower station S then just consumes power from the grid. This powerconsumption makes it possible to operate basic load units such asnuclear power stations or else coal-fired steam blocks at high powereven at times when the load is low, thus making it possible to makebetter use of their high investments. At times when there is a mediumload on the grid, the storage power station S is shut down, and theentire power demand is covered by the power stations G1 to G3, which areoperated close to their best operating point. At peak load times, theswitch 112 is closed and the turbine T is driven by the energy storagefluid which has been stored in the storage volume 100, and itself drivesthe generator GS, from which a power demand which cannot be covered bythe power stations G1 to G3 is fed into the grid. The invention nowmakes use of the knowledge that the motor MS in a storage system S canalso be operated as a secondary load, analogously to a “bias voltage” inthe electricity grid, even at times when there is a medium or highelectricity demand. The storage system S is, for example, operated insuch a way that the mass flow passed from the compressor V to thestorage volume 100 during normal operation is equal to the mass flowflowing out via the turbine T. Depending on the electricity price to beachieved or to be paid for at any given time, the storage system can inthis case also be operated, of course, in the storage mode or in thedischarge mode; the critical factor is for the motor MS to apply a loadto the electricity grid N even when the net power output is positive sothat, in global terms, the storage power station S does not represent aload. When sudden changes occur in the power demand on the storagesystem S, such as those, and to a particular extent, which occur in theevent of failure of one of the power stations G1 to G3 and when a majorload is connected to the grid, this secondary load can be changedconsiderably more efficiently and more quickly than the capability toprovide additional power. If, by way of example, one of the powerstations G1 to G3 has to be disconnected from the grid, the powerconsumption of the motor MS is, according to the invention, reduced by asimple circuitry means, which are known per se, or the switch 111 isopened entirely. This results in additional power being availablevirtually instantaneously, which was previously consumed by the motorMS, for the loads M1 to M8. In this case, it is possible to continueoperating the turbine T without problems with energy storage fluidprovided from the storage volume 100. In a next step, the power of theturbine T can, for example, be increased or it can be started up; inaddition, further power stations which are connected to the electricitygrid can increase their power or can connect additional resources to theelectricity grid in order to compensate for the initial power stationfailure; the motor MS and thus the compressor V in the storage system Scan then resume operation successively.

Conversely, it is, of course also possible, when a load M1 to M8 isdisconnected from the grid, to compensate for the drop in the powerconsumption in the grid N in a first step by immediately and quicklyincreasing the power consumption in the compressor V, in which case thischange in power can be taken over slowly and successively by the powerstations G1 to G3 and the turbine T, during which process the compressorV can be returned to its initial operating state.

The storage power station S is illustrated in a highly schematic form inFIG. 1. FIG. 2 shows an example of an embodiment of a storage powerstation S. The power consuming machine formed by the compressor V inthis case comprises two compressor runs, each having two compressors andtwo coolers. A first compressor 11 or 13 in each compressor runcompresses air to an intermediate pressure. The air is intermediatelycooled in a cooler 21 or 23, and is compressed in a second compressor 12or 14 to a final pressure, which is typically in a range from 30 to 100bar, or 50 to 100 bar. The compressors are driven by drive motors MS1,MS2, MS3 and MS4. The compressed air flows through a throttle andshut-off element 3 into the storage volume 100. Stored air flows via athrottle and shut-off element 4 to the turbine unit T. Within thisturbine unit T, the air first of all flows through an exhaust gas heatexchanger 5, where it is heated, for example, to 550° C. The air is thenexpanded in an air turbine 6 to a pressure of around 10 to 15 bar. Thestate of the air at the output from the air turbine 6 is in factcomparable to the state at the compressor outlet of a gas turbine set.For this reason, the combustion chamber 7 and the turbine 8 of a gasturbine set can very particularly advantageously be arranged downstreamfrom the air turbine. A fuel is burnt in the air in a manner known perse in the combustion chamber 7, resulting in the production of acompressed hot gas, which is expanded in the turbine 8, producing work,to approximately the environmental pressure. The expanded hot gas isoptionally reheated in a further burner 9, and then flows through theexhaust gas heat exchanger 5, in which the residual heat from theexhaust gas is transferred to the supply air to the air turbine 6. Theair turbine 6 and the gas turbine 8 in the turbine unit are arranged ona common shaft, and drive the generator GS. In contrast to aconventional gas turbine set, the compressor and turbine aremechanically completely decoupled from one another and, as a result ofthe intermediate storage volume in the flow path, the fluid-mechanicalcoupling also has a certain amount of elasticity. This makes it possiblefor the turbine unit T and the compressor unit V to be operatedindependently of one another, in such a manner, as described above, toreact in a very highly flexible manner to different power demands bymeans of two mechanisms, specifically by means of the power consumptionof the compressor unit and the power output of the turbine unit, and toincrease the net power output virtually instantaneously, in particularby switching off compressors which consume power. In this case, thecompressor runs, which are arranged in parallel in the mass flow, canlikewise be regulated independently of one another, thus furthersimplfying the power regulation of the entire storage system S.

It is advantageous for the controllability of the storage system for twoor more independently controllable compressor runs to be arranged inparallel in the mass flow as power loads and likewise for two or moreturbine units T to be connected to a storage volume in parallel in themass flow, as power generators. By way of example, FIG. 3 shows anoperating concept for a storage power station having four compressorruns and two turbine units. In this case, 100% power is defmed as thenet power output P_(NET) which results when both turbine units and allfour compressor runs are being operated at maximum power in anequilibrium state with respect to the mass balance of the storage volume100. The line which crosses the graph diagonally and is annotatedP_(NET) represents the net power output. The part annotated P_ below100% is the respective power consumption of the compressors. In a firstoperating area, which is annotated 4V0T, starting at −200% net poweroutput, that is to say 200% net power consumption, all four compressorruns and none of the turbines are in operation. As the power consumptionfalls, the power consumption of all four compressor runs is slowlyreduced, until one of the compressor runs is taken out of operation atone point. Three compressor runs are then operated with full powerconsumption, which can likewise be reduced slowly; this area isannotated 3V0T. This is followed by an area 2V0T with a lower net powerconsumption, in which two compressor runs and no turbine units areoperated. Following this, a first turbine unit is operated, and all fourcompressor runs are operated at the same time. In the area 3V1T, threecompressor runs and one turbine unit are in operation, and onecompressor run and one turbine unit are in operation in the area 1V1T,and so on. At 150% net power output, the second turbine unit is startedup, with two compressor runs being operated at the same time. Themaximum peak load net power is achieved when both turbine units arebeing operated at full load and no compressor run is being operated,that is to say in the area 0V2T. The net power output is then 300%. Thepower which is in each case shown below 0% is the respective powerconsumption of the compressors, and represents the power which can bemade available immediately as additional net power in the mannerdescribed above. Equilibrium operation is achieved, for example, whenboth turbine units and all four compressor runs are running on fullload, thus resulting in 100% net power output; the power consumption ofthe compressors is then 200%; this means that, according to theoperating method according to the present invention, the storage powerstation is able to compensate immediately and without any delay for thefailure of one power station block whose power corresponds to twice itsown rated power! This capability for frequency support and the widecontrol range underscore the superiority of a storage power station thatis operated according to the invention.

FIG. 4 illustrates, schematically, the power dynamic response which canbe achieved by means of the method according to the invention. Thevertical graph axis shows the net power output P_(NET), with negativevalues indicating power consumption, while the horizontal graph axisshows the time. This is based on an initial operating state in which, asalready described a number of times, the power consuming machines arerunning at full power, and the power generating machines are actuallyjust synchronized to the grid, or are being operated at a very lowpower, up to a maximum of 20% of the maximum power. Furthermore,quantitatively, it is assumed that, when the power generating machinesare being operated on full load in the steady state, two thirds of thetotal power generated is required for compression of the working fluid,and that the power consuming machines are designed for the maximum powerat this operating point. It would, of course, also be possible to designthe power consuming machines to be larger, and thus to cover an evenwider power range. In the initial operating state, the net power outputis −200%; power is thus drawn from the grid. At the time t=T₀, a maximumamount of additional power is drawn from the power generating systemthat is being operated according to the invention. This then reacts todisconnection of the power consuming machines so that, in practice, 200%power is released instantaneously; the net power output is then 0%. Evenduring controlled running down of compressors that are being used aspower consuming machines, it is possible to achieve typical powergradients around 120% per minute, with respect to the system ratedpower, which has already been defined a number of times! At the sametime, the power output from the power generating machines is increased,in fact, leads considerably more slowly to a further increase in powerup to 300%. It must be stressed that the additional useful power in astorage system such as an air storage system can be produced per se veryquickly although, in all cases this takes place at least one order ofmagnitude more slowly than is possible by reducing or switching off thepower consumption of the power consuming machines in the storage powerstation. Typically, it can be assumed that the power generating machinecan accept power with a gradient of around 15% per minute.

The dashed line shows the dynamic response with which the power stationsystem can advantageously react to a falling power demand. In this case,a decreasing net power output is first of all achieved by controlledacceleration of the power consuming machine at, for example, 120% perminute, thus making it possible to achieve a reduction in the net poweroutput of around 200% of the system rated power in 100 seconds. In theevent of greater load changes, the power output of the power generatingmachine is also changed. This is where one point of interest comes intoplay. A storage system of the described type and operated according tothe invention allows rapidly successive load cycles of up to 200% of thesystem rated power to be followed without having to subject thermallyhighly loaded components to an alternating load. The power regulationcan be carried out completely by the power consuming machines, withinthis order of magnitude. Reference should once again be made to FIG. 2,in order to estimate its alternating temperature load. If the storagepressure is assumed to be 100 bar, with the same pressure ratio in eachof the series connected compressors 11 and 12 or 13 and 14, compressionfrom an environmental state at 15° C. and intermediate cooling in thecooler 21, 23 to ambient temperature are achieved subject to theprecondition of isotropic compression, and maximum temperatures oflittle more than 300° C., and this is still around 250° C. with astorage pressure of 50 bar. These temperatures are, of course,considerably lower than those in the power consuming machine, for whichreason alternating loads pose considerably less loads on the structures.As has been mentioned a number of times above, the power range to becovered solely by compressor regulation can be increased further bydesigning the compressors to be appropriately larger.

One additional advantage of the method according to the invention isthat the technology of air storage turbines and their use for peak loadcoverage are well known and proven in engineering. Furthermore, provenstandard components can be used to a wide extent for the construction ofa power station that is to be operated according to the invention.

LIST OF REFERENCE SYMBOLS

-   3 Shut-off and throttling element-   4 Shut-off and throttling element-   5 Heat exchanger, exhaust gas heat exchanger, recuperator-   6 Air turbine-   7 Combustion chamber-   8 Gas turbine-   9 Duct firing-   11 Compressor-   12 Compressor-   13 Compressor-   14 Compressor-   21 Intercooler-   22 Air cooler-   23 Intermediate cooler-   24 Air cooler-   100 Storage volume-   111 Switch-   112 Switch-   113 Grid switch-   114 Regulator-   G1, G2, G3-   Power stations-   GS Generator for the power generating machine in the storage power    station-   M1, M2, M3, M4, M5, M6, M7, M8-   Loads-   MS Drive motor for the power consuming machine in the storage power    station-   MS1, MS2, MS3, MS4-   Drive motors for the power consuming machine in the storage power    station-   S Storage power station-   T Turbine unit, power generating machine-   V Compressor unit, power consuming machine-   P_(NET) Net power output-   P_ Power consumption of the power consuming machine

1. A method for power matching in an electricity grid, the grid comprising at least two power generating plants supplying power output into the grid, at least two power loads consuming power from the grid, at least one storage plant, at least one storage volume, at least one power generating machine for operation with an energy storage fluid which is stored in the storage volume, the power generating machine being connected to a generator which supplies electrical power during operation, at least one power consuming machine for feeding energy storage fluid into the storage volume, the power consuming machine being connected to a motor which consumes electrical power during operation, wherein, in a first operating state, an overall power supply includes the sum of the power output supplied from all the power generating plants and from the power generating machine and equals an overall power consumption that includes the sum of the power which is consumed by all the power loads and by the power consuming machine, such that the grid is in equilibrium, comprising: upon a sudden change in power demanded from the storage plant, controlling the power consumption of the power consuming machine such as to maintain the equilibrium between the overall power consumption and the overall power supply into the grid, and changing the power consumption of the power consuming machine in a direction opposite to the direction taken during controlling, with the changing in the power consumption being carried out slower than during controlling, and the changing being at least partially compensated for by changing the power output of the power generating machine, such that, when an initial rise occurs in the power demand, the power consumption of the power consuming machine is reduced, and the power output of the power generating machine is successively increased with the power consumption of the power consuming machine being increased, and when an initial drop occurs in the power demand, the power consumption of the power consuming machine is increased, and the power output of the power generating machine is successively reduced with the power consumption of the power consuming machine being reduced.
 2. The method as claimed in claim 1, further comprising: carrying out power matching by controlling the power consumption of the at least one power consuming machine in the at least one storage plant and any frequency response capabilities which may be present, wherein the power output from the at least one power generating machine of the at least one storage plant and other power plants connected to the grid is maintained constant.
 3. The method as claimed in claim 1, wherein power consumption of the power consuming machine is reduced when one of the power generating plants is disconnected from the grid or when one of the loads is connected to the grid.
 4. The method as claimed in claim 3, wherein the drive motor for the power consuming machine is completely disconnected from the grid.
 5. The method as claimed in claim 1, wherein power consumption of the power consuming machine is increased when one of the loads is disconnected from the grid or is rapidly deloaded.
 6. The method as claimed in claim 1, further comprising: operating the at least one power consuming machine in the at least one storage plant at at least 80% of its maximum power consumption in order to maintain a maximum power dynamic response, and synchronizing and connecting the generator of the at least one power generating machine in said storage plant to the grid, and operating the power generating machine at a minimum permissible power.
 7. The method as claimed in claim 6, further comprising: operating the power generating machine at less than 20% of its maximum power output.
 8. (canceled)
 9. (canceled)
 10. The method as claimed in claim 2, wherein power consumption of the power consuming machine is reduced when one of the power generating plants is disconnected from the grid or when one of the loads is connected to the grid.
 11. The method as claimed in claim 10, wherein the drive motor for the power consuming machine is completely disconnected from the grid.
 12. The method as claimed in claim 2, wherein power consumption of the power consuming machine is increased when one of the loads is disconnected from the grid or is rapidly deloaded.
 13. The method as claimed in claim 2 further comprising, operating the at least one power consuming machine in the at least one storage plant at at least 80% of its maximum power consumption in order to maintain a maximum power dynamic response, and synchronizing and connecting the generator of the at least one power generating machine in said storage plant to the grid, and operating the power generating machine at a minimum permissible power.
 14. The method as claimed in claim 3 further comprising, operating the at least one power consuming machine in the at least one storage plant at at least 80% of its maximum power consumption in order to maintain a maximum power dynamic response, and synchronizing and connecting the generator of the at least one power generating machine in said storage plant to the grid, and operating the power generating machine at a minimum permissible power.
 15. The method as claimed in claim 4 further comprising, operating the at least one power consuming machine in the at least one storage plant at at least 80% of its maximum power consumption in order to maintain a maximum power dynamic response, and synchronizing and connecting the generator of the at least one power generating machine in said storage plant to the grid, and operating the power generating machine at a minimum permissible power.
 16. The method as claimed in claim 5 further comprising, operating the at least one power consuming machine in the at least one storage plant at at least 80% of its maximum power consumption in order to maintain a maximum power dynamic response, and synchronizing and connecting the generator of the at least one power generating machine in said storage plant to the grid, and operating the power generating machine at a minimum permissible power.
 17. The method as claimed in claim 13, further comprising: operating the power generating machine at less than 20% of its maximum power output.
 18. The method as claimed in claim 14, further comprising: operating the power generating machine at less than 20% of its maximum power output.
 19. The method as claimed in claim 15, further comprising: operating the power generating machine at less than 20% of its maximum power output.
 20. The method as claimed in claim 16, further comprising: operating the power generating machine at less than 20% of its maximum power output.
 21. The method as claimed in claim 6, further comprising: operating the power generating machine at less than 10% of its maximum power output.
 22. The method as claimed in claim 13, further comprising: operating the power generating machine at less than 10% of its maximum power output. 